AI agents don't have credit cards. AgentFuel gives agents a single API key — funded with USDT or BTC — that proxies calls to Replicate, Anthropic, and ElevenLabs. No billing accounts. No per-service keys. Just fuel and go.
Three steps to go from zero to calling any API.
af_ key is issued to the memo/tag of your deposit. Store it securely — it's your identity.Authorization: Bearer af_... and route all API calls through https://agentfuel.dev/v1/.One endpoint per service. Same request format as the upstream APIs.
1,000 credits = $1 USD. No subscriptions. Credits never expire.
Deposit crypto to receive API credits. Minimum $10 per deposit.
af_ key is derived from your memo + deposit hash. If you provided an existing key, credits are added to it.Authorization header. Credits are deducted per response. Check balance anytime in the Balance tab.af_ and issued after crypto deposit.# Base URL for all AgentFuel endpoints BASE_URL=https://agentfuel.dev/v1 # Set your key once, use everywhere AF_KEY=af_d9f3a2b1c4e5f6789012345678901234
curl https://agentfuel.dev/v1/balance \ -H "Authorization: Bearer $AF_KEY" # Response: { "credits_remaining": 8432, "credits_used": 1568, "credits_total": 10000, "usd_value": 8.43, "usage_by_service": { "replicate": 1120, "anthropic": 336, "elevenlabs": 112 } }
api.replicate.com — just swap the base URL and use your af_ key.# Generate an image with FLUX Schnell (4 credits) curl -X POST https://agentfuel.dev/v1/replicate/predictions \ -H "Authorization: Bearer $AF_KEY" \ -H "Content-Type: application/json" \ -d '{ "version": "5f24084160c9089501c1b3545d9be3c27883ae2239b6f412990e82d4a6210f8f", "input": { "prompt": "enchanted forest at dusk, bioluminescent mushrooms", "num_outputs": 1, "output_format": "webp" } }' # Returns standard Replicate prediction object # Poll GET /v1/replicate/predictions/{id} until status=succeeded
curl https://agentfuel.dev/v1/replicate/predictions/abc123 \ -H "Authorization: Bearer $AF_KEY" # Credits deducted when status transitions to "succeeded"
# fofr/realvisxl-v3-multi-controlnet-lora — illusion ControlNet curl -X POST https://agentfuel.dev/v1/replicate/predictions \ -H "Authorization: Bearer $AF_KEY" \ -H "Content-Type: application/json" \ -d '{ "version": "1a3ade8e0dda7e1dbc652fe9ceda0f3cf0cc2ced1cccd217a035a3bc1a8a9f08", "input": { "prompt": "enchanted forest with glowing fairies", "controlnet_1": "illusion", "controlnet_1_image": "https://example.com/reference.jpg", "controlnet_1_conditioning_scale": 0.7, "width": 768, "height": 768, "guidance_scale": 7.5, "num_inference_steps": 40, "apply_watermark": false } }'
api.anthropic.com. Vision (image inputs) supported.# Text message to Claude Haiku (~0.4 cr/1K input tokens) curl -X POST https://agentfuel.dev/v1/anthropic/messages \ -H "Authorization: Bearer $AF_KEY" \ -H "Content-Type: application/json" \ -d '{ "model": "claude-haiku-4-5-20251001", "max_tokens": 1024, "messages": [{ "role": "user", "content": "Describe this image in detail." }] }' # Vision: pass image URL in content array "content": [ { "type": "image", "source": { "type": "url", "url": "https://..." } }, { "type": "text", "text": "Rate this image 1-10" } ]
audio/mpeg.# Generate speech — 2 cr per 1K chars (Turbo v2.5) curl -X POST \ https://agentfuel.dev/v1/elevenlabs/text-to-speech/21m00Tcm4TlvDq8ikWAM \ -H "Authorization: Bearer $AF_KEY" \ -H "Content-Type: application/json" \ -d '{ "text": "Your design is ready.", "model_id": "eleven_turbo_v2_5", "voice_settings": { "stability": 0.5, "similarity_boost": 0.75 } }' \ --output speech.mp3
error field.| Code | Meaning | Action |
|---|---|---|
| 401 | Invalid or missing key | Check your af_ key |
| 402 | Insufficient credits | Deposit more crypto via Fuel Up tab |
| 429 | Rate limit exceeded | Max 60 requests/min per key |
| 502 | Upstream API error | Retry; check upstream status pages |
| 503 | Service unavailable | Temporary outage; retry with backoff |
{
"error": "insufficient_credits",
"message": "This request costs 28 credits. Balance: 12.",
"credits_required": 28,
"credits_available": 12,
"deposit_url": "https://agentfuel.dev"
}
Enter your AgentFuel key to check your credit balance and usage history.
af_ and 32 alphanumeric characters.| Timestamp | Service | Model / Endpoint | Credits |
|---|